Pipe-parting overshot



Aug. 18, 1925.

P. F. YUNGLING PIPE PARTING OVERSHOT Flled Nov. 5, 1922 V l A f illllllllllllllhI Il f. ,Vial @7 the device is vapplied.

'the line 3 3 of Fig. 2.

Patented Aug. 18, 1925.

UNITED STATES.

IPAULF. YUNGLING, OF LOS ANGELES, CALIFORNIA.

PIPE-rename ovERsHo'r.

Application led November 3, 1922. Serial 110.598,882.

To all 'whom it may concern. d

Be it -known that I, PAUL F. Y'uNeLING, 'a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have inyented n ew and useful Improvements in .Pipe-Parting Overshots, of which the following is a specification.

My invention relates to pipe parting overshots adapted for use in therecovery of drill pipe or casing from wells, 'a nd a -purposelof my invention is the provision ot an overshot of this character which is operable .to eilect the parting of two sections of drill pipe or casing and the subsequentrecovery of the disconnected sections all by the more loweringand elevation of the overshot, and without the 'necessity of rotating the over-- shot and its attendant disadvantages. 4 Heretofore it has lbeen the practice to grapple the drill stem or casing at or n ear the upper end and vapply sufficient pulling power to break the pipe, and inwthis operation there is no way of predetermining the point at which the pipe will break,'and it requires a pull of one hundred fifty to two hundred tons to break the pipe.

The principal object of my invention'is to i make a device which will gripthepipe at a d predetermined pointend which will by aps plying a `pull of forty or fifty tons weaken the pipe and break it at the point at which Although I will describe only. one form of pipe parting overshot .embodying my invention, it is to be understood that various lchanges and modifications may be made herein without departing from 'the spirit of the invention and the spirit and scope of the appended claim.

In Vthe accompanying drawings, Y n Figure 1 is a view showing in vertical section one form of pipe parting overshot. em' .bodyingmy invention -in applied position with respect to aI drill pipe; l V

Fig. 2 is a viewsimilar to'Fig. 1 showing the over-shot in parting positionY with respect to two sections of drill pipe; and

Fig. 3 is a transverse sectional view on Referring specifically to the drawings, in

which similar reference characters refer to similar parts, my invention in its present embodiment comprisesV an overshot casing 15 adapted for connection at its upper end with a supporting collar 16A to which latter the usual operating mea-lisis adapted tobe connec'ted for effecting the lowering and elevation of the overshot i-n a well. The lower end of the casing 15 is adapted for connection in the usual manner with a bowl 17. Between the ends of the casing are longitudinally extending recessed portions 18 oommunicating at their lower ends with slots 1%). These recesses and slots are circumferen- Atially spaced to accommodate a plunality of dogs 20, all of the dogs being mountedl for swinging movement above horizontal axes by means of pins 21 secured within the walls .of the slots 19.

Each dog 20 comprises yan elongated shank 20a which is tapered to provide a pointed end 2 0",l the opposite or wide end being provided with an integrally formed head 20c through which the pivot pin 21 extends. TheA endl of the head 2Oc is rounded as indicated at 20d so as to have engagement with the rounded bottom wall of the slot 19 when the dog is inactive position, as shown in Figure 2. By thisarrangement it will be clear that the pivot pin 21 is vrelieved of any strain or stress exerted upon the dog to` prevent distortion of the pin :and insure Aproper operationof the dog at all times. The shank 2a is of triangular shape in cross sectionso as to pro-vide upon .its inner side ll-a llongitudinally extending crimping edge 20.

' The several dogs 20are mounted to occupy `an .inactive-position, as shown in Figure' 1, wherein theyl are disposed within the recesses 18 to allow of the application of the overshot casing to a length of drill pipe. The dogs are also capable of occupyingA an active position, shown in Figure 2,`in which -they are .projecting towiard the axis of the casing 15 through the medium of leaf springs 22 arranged in the manner shown;-

VIn operation, the overshot is lowered into the4 `well in'surrounding position with respect to the drill pipe and until the pointed dogs into the recesses 18 so as to allow of the casing 15 being lowered to the desired point. With the dogs disposed beneath the connecting collar v23 it will be clear that upward movement of 'the oveishot casing will cause the pointed ends of the dogs to be forced between the pipe sections and the collar 23, and because ofthe construction of the dogs they will eect the longitudinal crimping of the pipe section 25 at circumferentially spaced points, as clearly shown in Figure 3. Under this crimping action, the major portions of the threads of the pipe section 25 are disengaged from the threads of the connecting collar 23 so that upon continued upward pull upon the overshot the collar 23 can be disengaged from vthe `pipe section so as to allow the removal of the upper pipe section 24.

The pipe sections 24 and 25 have the regie lar tapered pipe threads upon their meeting ends, and the collars 23 are the usual pipe couplings. The dogs are in reality heavy chisels, and the points of the dogs rub against the casings 24 and 25 and spread out to pass the couplings, and these points will engage the lower edge of a coupling when the device is moved upwardly and the points of the chise-ls dig into the external threads of the section and the internal threads ofthe coupling 23 and out more or less of a groove.

The continual upward pull on the overshot will tend to expand the couplingiand at the same time crimp the pipe. The more the lower end of the coupling is expanded, the weaker the joint becomes because the threads at the extreme ends of the pipe 25 are smaller in diameter than the lower threads. The result is that the pipe 25 is crimped inwardly .and grooved and the coupling 23 is bulged outwardly, and the process is continued and power applied until the joint breaks.

It is only a question of making the dogs 2O strong enough and making the easing 15 and the pulling parts above t-he casing strong enough, land applying power enough to break the drill pipe at the point preweasel viously determined upon and engaged by the dogs 20.

After the disengagement of the lower drill pipe section 25 from the collar 23 the upper drill pipe section 24 and its collar 23 will be supported by the dogs 20. It should be noted that the lower portion of the dogs 20 about the pivot 21 rests upon the wall of the casing 15 at 20d. The wall of the casing 15 will be made of sufficient strength to support the section of the drill pipe 24 and its collar 23 and will prevent the dogs 20 from turning downwardly of their pivots 21. However, in case the dogs 2l should turn downwardly they will not assume a position parallel to the walls of the casing 15 in view of the widened head 20c sand the position of the pivot 21, and would at most, occupy a position extending downwardly and obliquely away from 'the walls of the casing 15, thus preventing the drill pipe section 24 and its collar 23 from falling downwardly in the well. The overshot, with its section of drill pipe, is then raised from the well in any conventional or preferred manner.

After the removal of the pipe section from the well has been eifected, it will be manifest that the dogs 20 can be removed from the collar 23 to permit of the overshot being again applied to the succeeding section of drill pipe.

vWhat I claim is:

A pipe parting overshot comprising a body, a pointed dog carried by said body adapted to be forced between a pipe coupling and one of the pipe sections connected thereby, said dog being provided with a crimping edge adapted to crimp the pipe section inwardly away from the interior surface of said coupling.

In testimony whereof I have signed my name to this specification.

PAUL F. YUNGLING. 

